The present invention relates to a system for disposing of waste water from the black and grey water holding tanks in a recreational vehicle (RV) in such a way as to flush the black water tank thoroughly.
The waste water in an RV is commonly referred to as grey water and black water. The grey water is the waste from the kitchen sink, dish washing water, and water from the bathroom sink and shower. The black water is the water and waste collected in its holding tank from the toilet.
At present these two types of waste water are handled separately in their respective holding tanks, and are joined by a "Y" connection in the sewer pipe only just before being let out of the RV into the sewer line. The two types of waste are not mixed until they come together in the sewer pipe.
The flushing of the toilet in an RV is not the same as flushing a conventional toilet. There is no accumulation of water held in a toilet tank which is released to facilitate the flush. The user steps on a valve or otherwise manually operates a valve to release water only while the valve is held open. The amount of water used in the flush can be as little as 10% of the amount of water used in a conventional toilet. Because of this, the black water tank has much less water than required to thoroughly flush the solids from the tank when emptying the tank.
U.S. Pat. No. 4,868,932 discloses a holding tank flushing system for a recreational vehicle which uses a supplementary self-contained cleaning fluid distribution system. This is an expensive solution to the problem of flushing the RV holding tanks. This patent does show the Y or T 18, at which the grey water and sewage lines 14 and 16 meet, as well as manually operated drain shut off valves 22 and 24 in each line.
U.S. Pat. No. 3,594,825 describes a water circulation system for a camper or boat, wherein grey water can be used to flush the toilet in order to conserve water usage.
It is therefore an object of the invention to provide a simple, inexpensive system for flushing the black water holding tank in recreational vehicles.
It is also an object of this invention to provide a waste water disposal system for recreational vehicles which employs grey water to flush the black water holding tank.